hydroxide ion	[[$\text{OH}^{-}$]]
sulphate ion	[[$\text{SO}_4^{2-}$]]
phosphate ion	[[$\text{PO}_4^{3-}$]]
nitrate ion	[[$\text{NO}_3^{-}$]]
carbonate ion	[[$\text{CO}_3^{2-}$]]
acetate ion	[[$\text{CH}_3\text{COO}^{-}$]]
ammonium ion	[[$\text{NH}_4^{+}$]]

Note that a sulphate in Britain is a sulfate on the other side of the Atlantic!